/**
* http://github.com/valums/file-uploader
* 
* Multiple file upload component with progress-bar, drag-and-drop. 
* © 2010 Andrew Valums andrew(at)valums.com 
* 
* Licensed under MIT, GNU GPL and GNU LGPL 2 or later.
*  
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>. 
*/

var qq = qq || {};

/**
* Class that creates our multiple file upload widget
*/
qq.FileUploader = function (o) {
    this._options = {
        // container element DOM node (ex. $(selector)[0] for jQuery users)
        element: null,
        // url of the server-side upload script, should be on the same domain
        action: '/server/upload',
        // additional data to send, name-value pairs
        params: {},
        // ex. ['jpg', 'jpeg', 'png', 'gif'] or []
        allowedExtensions: [],
        // size limit in bytes, 0 - no limit
        // this option isn't supported in all browsers
        sizeLimit: 0,
        onSubmit: function (id, fileName) { },
        onComplete: function (id, fileName, responseJSON) { },

        //
        // UI customizations

        template: '<div class="qq-uploader">' +
                '<div class="qq-upload-drop-area"><span>Drop files here to upload</span></div>' +
                '<div class="qq-upload-button">Upload a file</div>' +
                '<ul class="qq-upload-list"></ul>' +
             '</div>',

        // template for one item in file list
        fileTemplate: '<li>' +
                '<span class="qq-upload-file"></span>' +
                '<span class="qq-upload-spinner"></span>' +
                '<span class="qq-upload-size"></span>' +
                '<a class="qq-upload-cancel" href="#">Cancel</a>' +
                '<span class="qq-upload-failed-text">Failed</span>' +
            '</li>',

        classes: {
            // used to get elements from templates
            button: 'qq-upload-button',
            drop: 'qq-upload-drop-area',
            dropActive: 'qq-upload-drop-area-active',
            list: 'qq-upload-list',

            file: 'qq-upload-file',
            spinner: 'qq-upload-spinner',
            size: 'qq-upload-size',
            cancel: 'qq-upload-cancel',

            // added to list item when upload completes
            // used in css to hide progress spinner
            success: 'qq-upload-success',
            fail: 'qq-upload-fail'
        },
        messages: {
            //serverError: "Some files were not uploaded, please contact support and/or try again.",
            typeError: "{file} has invalid extension. Only {extensions} are allowed.",
            sizeError: "{file} is too large, maximum file size is {sizeLimit}.",
            emptyError: "{file} is empty, please select files again without it."
        },
        showMessage: function (message) {
            alert(message);
        }
    };

    qq.extend(this._options, o);

    this._element = this._options.element;

    if (this._element.nodeType != 1) {
        throw new Error('element param of FileUploader should be dom node');
    }

    this._element.innerHTML = this._options.template;

    // number of files being uploaded
    this._filesInProgress = 0;

    // easier access
    this._classes = this._options.classes;

    this._handler = this._createUploadHandler();

    this._bindCancelEvent();

    var self = this;
    this._button = new qq.UploadButton({
        element: this._getElement('button'),
        multiple: qq.UploadHandlerXhr.isSupported(),
        onChange: function (input) {
            self._onInputChange(input);
        }
    });

    this._setupDragDrop();
};

qq.FileUploader.prototype = {
    setParams: function (params) {
        this._options.params = params;
    },
    /**
    * Returns true if some files are being uploaded, false otherwise
    */
    isUploading: function () {
        return !!this._filesInProgress;
    },
    /**
    * Gets one of the elements listed in this._options.classes
    * 
    * First optional element is root for search,
    * this._element is default value.
    *
    * Usage
    *  1. this._getElement('button');
    *  2. this._getElement(item, 'file'); 
    **/
    _getElement: function (parent, type) {
        if (typeof parent == 'string') {
            // parent was not passed
            type = parent;
            parent = this._element;
        }

        var element = qq.getByClass(parent, this._options.classes[type])[0];

        if (!element) {
            throw new Error('element not found ' + type);
        }

        return element;
    },
    _error: function (code, fileName) {
        var message = this._options.messages[code];
        message = message.replace('{file}', this._formatFileName(fileName));
        message = message.replace('{extensions}', this._options.allowedExtensions.join(', '));
        message = message.replace('{sizeLimit}', this._formatSize(this._options.sizeLimit));
        this._options.showMessage(message);
    },
    _formatFileName: function (name) {
        if (name.length > 33) {
            name = name.slice(0, 19) + '...' + name.slice(-13);
        }
        return name;
    },
    _isAllowedExtension: function (fileName) {
        var ext = (-1 !== fileName.indexOf('.')) ? fileName.replace(/.*[.]/, '').toLowerCase() : '';
        var allowed = this._options.allowedExtensions;

        if (!allowed.length) { return true; }

        for (var i = 0; i < allowed.length; i++) {
            if (allowed[i].toLowerCase() == ext) {
                return true;
            }
        }

        return false;
    },
    _setupDragDrop: function () {
        function isValidDrag(e) {
            var dt = e.dataTransfer,
            // do not check dt.types.contains in webkit, because it crashes safari 4            
                isWebkit = navigator.userAgent.indexOf("AppleWebKit") > -1;

            // dt.effectAllowed is none in Safari 5
            // dt.types.contains check is for firefox            
            return dt && dt.effectAllowed != 'none' &&
                (dt.files || (!isWebkit && dt.types.contains && dt.types.contains('Files')));
        }

        var self = this,
            dropArea = this._getElement('drop');

        dropArea.style.display = 'none';

        var hideTimeout;
        qq.attach(document, 'dragenter', function (e) {
            e.preventDefault();
        });

        qq.attach(document, 'dragover', function (e) {
            if (isValidDrag(e)) {

                if (hideTimeout) {
                    clearTimeout(hideTimeout);
                }

                if (dropArea == e.target || qq.contains(dropArea, e.target)) {
                    var effect = e.dataTransfer.effectAllowed;
                    if (effect == 'move' || effect == 'linkMove') {
                        e.dataTransfer.dropEffect = 'move'; // for FF (only move allowed)    
                    } else {
                        e.dataTransfer.dropEffect = 'copy'; // for Chrome
                    }
                    qq.addClass(dropArea, self._classes.dropActive);
                    e.stopPropagation();
                } else {
                    dropArea.style.display = 'block';
                    e.dataTransfer.dropEffect = 'none';
                }

                e.preventDefault();
            }
        });

        qq.attach(document, 'dragleave', function (e) {
            if (isValidDrag(e)) {

                if (dropArea == e.target || qq.contains(dropArea, e.target)) {
                    qq.removeClass(dropArea, self._classes.dropActive);
                    e.stopPropagation();
                } else {

                    if (hideTimeout) {
                        clearTimeout(hideTimeout);
                    }

                    hideTimeout = setTimeout(function () {
                        dropArea.style.display = 'none';
                    }, 77);
                }
            }
        });

        qq.attach(dropArea, 'drop', function (e) {
            dropArea.style.display = 'none';
            self._uploadFileList(e.dataTransfer.files);
            e.preventDefault();
        });
    },
    _createUploadHandler: function () {
        var self = this,
            handlerClass;

        if (qq.UploadHandlerXhr.isSupported()) {
            handlerClass = 'UploadHandlerXhr';
        } else {
            handlerClass = 'UploadHandlerForm';
        }

        var handler = new qq[handlerClass]({
            action: this._options.action,
            onProgress: function (id, fileName, loaded, total) {
                // is only called for xhr upload
                self._updateProgress(id, loaded, total);
            },
            onComplete: function (id, fileName, result) {
                self._filesInProgress--;

                // mark completed
                var item = self._getItemByFileId(id);
                qq.remove(self._getElement(item, 'cancel'));
                qq.remove(self._getElement(item, 'spinner'));

                if (result.success) {
                    qq.addClass(item, self._classes.success);
                } else {
                    qq.addClass(item, self._classes.fail);

                    if (result.error) {
                        self._options.showMessage(result.error);
                    }
                }

                self._options.onComplete(id, fileName, result);
            }
        });

        return handler;
    },
    _onInputChange: function (input) {

        if (this._handler instanceof qq.UploadHandlerXhr) {

            this._uploadFileList(input.files);

        } else {

            if (this._validateFile(input)) {
                this._uploadFile(input);
            }

        }

        this._button.reset();
    },
    _uploadFileList: function (files) {
        var valid = true;

        var i = files.length;
        while (i--) {
            if (!this._validateFile(files[i])) {
                valid = false;
                break;
            }
        }

        if (valid) {
            var i = files.length;
            while (i--) { this._uploadFile(files[i]); }
        }
    },
    _uploadFile: function (fileContainer) {
        var id = this._handler.add(fileContainer);
        var name = this._handler.getName(id);
        this._options.onSubmit(id, name);
        this._addToList(id, name);
        this._handler.upload(id, this._options.params);
    },
    _validateFile: function (file) {
        var name, size;

        if (file.value) {
            // it is a file input            
            // get input value and remove path to normalize
            name = file.value.replace(/.*(\/|\\)/, "");
        } else {
            // fix missing properties in Safari
            name = file.fileName != null ? file.fileName : file.name;
            size = file.fileSize != null ? file.fileSize : file.size;
        }

        if (!this._isAllowedExtension(name)) {
            this._error('typeError', name);
            return false;

        } else if (size === 0) {
            this._error('emptyError', name);
            return false;

        } else if (size && this._options.sizeLimit && size > this._options.sizeLimit) {
            this._error('sizeError', name);
            return false;
        }

        return true;
    },
    _addToList: function (id, fileName) {
        var item = qq.toElement(this._options.fileTemplate);
        item.qqFileId = id;

        var fileElement = this._getElement(item, 'file');
        qq.setText(fileElement, this._formatFileName(fileName));
        this._getElement(item, 'size').style.display = 'none';

        this._getElement('list').appendChild(item);

        this._filesInProgress++;
    },
    _updateProgress: function (id, loaded, total) {
        var item = this._getItemByFileId(id);
        var size = this._getElement(item, 'size');
        size.style.display = 'inline';

        var text;
        if (loaded != total) {
            text = Math.round(loaded / total * 100) + '% from ' + this._formatSize(total);
        } else {
            text = this._formatSize(total);
        }

        qq.setText(size, text);
    },
    _formatSize: function (bytes) {
        var i = -1;
        do {
            bytes = bytes / 1024;
            i++;
        } while (bytes > 99);

        return Math.max(bytes, 0.1).toFixed(1) + ['kB', 'MB', 'GB', 'TB', 'PB', 'EB'][i];
    },
    _getItemByFileId: function (id) {
        var item = this._getElement('list').firstChild;

        // there can't be text nodes in our dynamically created list
        // because of that we can safely use nextSibling
        while (item) {
            if (item.qqFileId == id) {
                return item;
            }

            item = item.nextSibling;
        }
    },
    /**
    * delegate click event for cancel link 
    **/
    _bindCancelEvent: function () {
        var self = this,
            list = this._getElement('list');

        qq.attach(list, 'click', function (e) {
            e = e || window.event;
            var target = e.target || e.srcElement;

            if (qq.hasClass(target, self._classes.cancel)) {
                qq.preventDefault(e);

                var item = target.parentNode;
                self._handler.cancel(item.qqFileId);
                qq.remove(item);
            }
        });

    }
};

qq.UploadButton = function (o) {
    this._options = {
        element: null,
        // if set to true adds multiple attribute to file input      
        multiple: false,
        // name attribute of file input
        name: 'file',
        onChange: function (input) { },
        hoverClass: 'qq-upload-button-hover',
        focusClass: 'qq-upload-button-focus'
    };

    qq.extend(this._options, o);

    this._element = this._options.element;

    // make button suitable container for input
    qq.css(this._element, {
        position: 'relative',
        overflow: 'hidden',
        // Make sure browse button is in the right side
        // in Internet Explorer
        direction: 'ltr'
    });

    this._input = this._createInput();
};

qq.UploadButton.prototype = {
    /* returns file input element */
    getInput: function () {
        return this._input;
    },
    /* cleans/recreates the file input */
    reset: function () {
        if (this._input.parentNode) {
            qq.remove(this._input);
        }

        qq.removeClass(this._element, this._options.focusClass);
        this._input = this._createInput();
    },
    _createInput: function () {
        var input = document.createElement("input");

        if (this._options.multiple) {
            input.setAttribute("multiple", "multiple");
        }

        input.setAttribute("type", "file");
        input.setAttribute("name", this._options.name);

        qq.css(input, {
            position: 'absolute',
            // in Opera only 'browse' button
            // is clickable and it is located at
            // the right side of the input
            right: 0,
            top: 0,
            zIndex: 1,
            fontSize: '460px',
            margin: 0,
            padding: 0,
            cursor: 'pointer',
            opacity: 0
        });

        this._element.appendChild(input);

        var self = this;
        qq.attach(input, 'change', function () {
            self._options.onChange(input);
        });

        qq.attach(input, 'mouseover', function () {
            qq.addClass(self._element, self._options.hoverClass);
        });
        qq.attach(input, 'mouseout', function () {
            qq.removeClass(self._element, self._options.hoverClass);
        });
        qq.attach(input, 'focus', function () {
            qq.addClass(self._element, self._options.focusClass);
        });
        qq.attach(input, 'blur', function () {
            qq.removeClass(self._element, self._options.focusClass);
        });

        // IE and Opera, unfortunately have 2 tab stops on file input
        // which is unacceptable in our case, disable keyboard access
        if (window.attachEvent) {
            // it is IE or Opera
            input.setAttribute('tabIndex', "-1");
        }

        return input;
    }
};

/**
* Class for uploading files using form and iframe
*/
qq.UploadHandlerForm = function (o) {
    this._options = {
        // URL of the server-side upload script,
        // should be on the same domain to get response
        action: '/upload',
        // fires for each file, when iframe finishes loading
        onComplete: function (id, fileName, response) { }
    };
    qq.extend(this._options, o);

    this._inputs = {};
};
qq.UploadHandlerForm.prototype = {
    /**
    * Adds file input to the queue
    * Returns id to use with upload, cancel
    **/
    add: function (fileInput) {
        fileInput.setAttribute('name', 'qqfile');
        var id = 'qq-upload-handler-iframe' + qq.getUniqueId();

        this._inputs[id] = fileInput;

        // remove file input from DOM
        if (fileInput.parentNode) {
            qq.remove(fileInput);
        }

        return id;
    },
    /**
    * Sends the file identified by id and additional query params to the server
    * @param {Object} params name-value string pairs
    */
    upload: function (id, params) {
        var input = this._inputs[id];

        if (!input) {
            throw new Error('file with passed id was not added, or already uploaded or cancelled');
        }

        var fileName = this.getName(id);

        var iframe = this._createIframe(id);
        var form = this._createForm(iframe, params);
        form.appendChild(input);

        var self = this;
        this._attachLoadEvent(iframe, function () {
            self._options.onComplete(id, fileName, self._getIframeContentJSON(iframe));

            delete self._inputs[id];
            // timeout added to fix busy state in FF3.6
            setTimeout(function () {
                qq.remove(iframe);
            }, 1);
        });

        form.submit();
        qq.remove(form);

        return id;
    },
    cancel: function (id) {
        if (id in this._inputs) {
            delete this._inputs[id];
        }

        var iframe = document.getElementById(id);
        if (iframe) {
            // to cancel request set src to something else
            // we use src="javascript:false;" because it doesn't
            // trigger ie6 prompt on https
            iframe.setAttribute('src', 'javascript:false;');

            qq.remove(iframe);
        }
    },
    getName: function (id) {
        // get input value and remove path to normalize
        return this._inputs[id].value.replace(/.*(\/|\\)/, "");
    },
    _attachLoadEvent: function (iframe, callback) {
        qq.attach(iframe, 'load', function () {
            // when we remove iframe from dom
            // the request stops, but in IE load
            // event fires
            if (!iframe.parentNode) {
                return;
            }

            // fixing Opera 10.53
            if (iframe.contentDocument &&
                iframe.contentDocument.body &&
                iframe.contentDocument.body.innerHTML == "false") {
                // In Opera event is fired second time
                // when body.innerHTML changed from false
                // to server response approx. after 1 sec
                // when we upload file with iframe
                return;
            }

            callback();
        });
    },
    /**
    * Returns json object received by iframe from server.
    */
    _getIframeContentJSON: function (iframe) {
        // iframe.contentWindow.document - for IE<7
        var doc = iframe.contentDocument ? iframe.contentDocument : iframe.contentWindow.document,
            response;

        try {
            response = eval("(" + doc.body.innerText + ")");
            console.log(doc.body.innerText);
            //response = eval("(" + doc.body.innerHTML + ")");
        } catch (err) {
            alert(err);
            console.log(err);
            response = {};
        }

        return response;
    },
    /**
    * Creates iframe with unique name
    */
    _createIframe: function (id) {
        // We can't use following code as the name attribute
        // won't be properly registered in IE6, and new window
        // on form submit will open
        // var iframe = document.createElement('iframe');
        // iframe.setAttribute('name', id);

        var iframe = qq.toElement('<iframe src="javascript:false;" name="' + id + '" />');
        // src="javascript:false;" removes ie6 prompt on https

        iframe.setAttribute('id', id);

        iframe.style.display = 'none';
        document.body.appendChild(iframe);

        return iframe;
    },
    /**
    * Creates form, that will be submitted to iframe
    */
    _createForm: function (iframe, params) {
        // We can't use the following code in IE6
        // var form = document.createElement('form');
        // form.setAttribute('method', 'post');
        // form.setAttribute('enctype', 'multipart/form-data');
        // Because in this case file won't be attached to request
        var form = qq.toElement('<form method="post" enctype="multipart/form-data"></form>');

        var queryString = '?';
        for (var key in params) {
            queryString += '&' + key + '=' + encodeURIComponent(params[key]);
        }

        form.setAttribute('action', this._options.action + queryString);
        form.setAttribute('target', iframe.name);
        form.style.display = 'none';
        document.body.appendChild(form);

        return form;
    }
};

/**
* Class for uploading files using xhr
*/
qq.UploadHandlerXhr = function (o) {
    this._options = {
        // url of the server-side upload script,
        // should be on the same domain
        action: '/upload',
        onProgress: function (id, fileName, loaded, total) { },
        onComplete: function (id, fileName, response) { }
    };
    qq.extend(this._options, o);

    this._files = [];
    this._xhrs = [];
};

// static method
qq.UploadHandlerXhr.isSupported = function () {
    return typeof File != "undefined" &&
        typeof (new XMLHttpRequest()).upload != "undefined";
};

qq.UploadHandlerXhr.prototype = {
    /**
    * Adds file to the queue
    * Returns id to use with upload, cancel
    **/
    add: function (file) {
        return this._files.push(file) - 1;
    },
    /**
    * Sends the file identified by id and additional query params to the server
    * @param {Object} params name-value string pairs
    */
    upload: function (id, params) {
        var file = this._files[id],
            name = this.getName(id),
            size = this.getSize(id);

        if (!file) {
            throw new Error('file with passed id was not added, or already uploaded or cancelled');
        }

        var xhr = this._xhrs[id] = new XMLHttpRequest();
        var self = this;

        xhr.upload.onprogress = function (e) {
            if (e.lengthComputable) {
                self._options.onProgress(id, name, e.loaded, e.total);
            }
        };

        xhr.onreadystatechange = function () {
            // the request was aborted/cancelled
            if (!self._files[id]) {
                return;
            }

            if (xhr.readyState == 4) {

                self._options.onProgress(id, name, size, size);

                if (xhr.status == 200) {
                    var response;

                    try {
                        response = eval("(" + xhr.responseText + ")");
                    } catch (err) {
                        response = {};
                    }

                    self._options.onComplete(id, name, response);

                } else {
                    self._options.onComplete(id, name, {});
                }

                self._files[id] = null;
                self._xhrs[id] = null;
            }
        };

        // build query string
        var queryString = '?qqfile=' + encodeURIComponent(name);
        for (var key in params) {
            queryString += '&' + key + '=' + encodeURIComponent(params[key]);
        }

        xhr.open("POST", this._options.action + queryString, true);
        xhr.send(file);
    },
    cancel: function (id) {
        this._files[id] = null;

        if (this._xhrs[id]) {
            this._xhrs[id].abort();
            this._xhrs[id] = null;
        }
    },
    getName: function (id) {
        // fix missing name in Safari 4
        var file = this._files[id];
        return file.fileName != null ? file.fileName : file.name;
    },
    getSize: function (id) {
        // fix missing size in Safari 4
        var file = this._files[id];
        return file.fileSize != null ? file.fileSize : file.size;
    }
};

//
// Helper functions
//

var qq = qq || {};

//
// Useful generic functions

/**
* Adds all missing properties from obj2 to obj1
*/
qq.extend = function (obj1, obj2) {
    for (var prop in obj2) {
        obj1[prop] = obj2[prop];
    }
};

/**
* @return {Number} unique id
*/
qq.getUniqueId = (function () {
    var id = 0;
    return function () {
        return id++;
    };
})();

//
// Events

qq.attach = function (element, type, fn) {
    if (element.addEventListener) {
        element.addEventListener(type, fn, false);
    } else if (element.attachEvent) {
        element.attachEvent('on' + type, fn);
    }
};
qq.detach = function (element, type, fn) {
    if (element.removeEventListener) {
        element.removeEventListener(type, fn, false);
    } else if (element.attachEvent) {
        element.detachEvent('on' + type, fn);
    }
};

qq.preventDefault = function (e) {
    if (e.preventDefault) {
        e.preventDefault();
    } else {
        e.returnValue = false;
    }
};
//
// Node manipulations

/**
* Insert node a before node b.
*/
qq.insertBefore = function (a, b) {
    b.parentNode.insertBefore(a, b);
};
qq.remove = function (element) {
    element.parentNode.removeChild(element);
};

qq.contains = function (parent, descendant) {
    if (parent.contains) {
        return parent.contains(descendant);
    } else {
        return !!(descendant.compareDocumentPosition(parent) & 8);
    }
};

/**
* Creates and returns element from html string
* Uses innerHTML to create an element
*/
qq.toElement = (function () {
    var div = document.createElement('div');
    return function (html) {
        div.innerHTML = html;
        var element = div.firstChild;
        div.removeChild(element);
        return element;
    };
})();

//
// Node properties and attributes

/**
* Sets styles for an element.
* Fixes opacity in IE6-8.
*/
qq.css = function (element, styles) {
    if (styles.opacity != null) {
        if (typeof element.style.opacity != 'string' && typeof (element.filters) != 'undefined') {
            styles.filter = 'alpha(opacity=' + Math.round(100 * styles.opacity) + ')';
        }
    }
    qq.extend(element.style, styles);
};
qq.hasClass = function (element, name) {
    var re = new RegExp('(^| )' + name + '( |$)');
    return re.test(element.className);
};
qq.addClass = function (element, name) {
    if (!qq.hasClass(element, name)) {
        element.className += ' ' + name;
    }
};
qq.removeClass = function (element, name) {
    var re = new RegExp('(^| )' + name + '( |$)');
    element.className = element.className.replace(re, ' ').replace(/^\s+|\s+$/g, "");
};
qq.setText = function (element, text) {
    element.innerText = text;
    element.textContent = text;
};

//
// Selecting elements

qq.children = function (element) {
    var children = [],
    child = element.firstChild;

    while (child) {
        if (child.nodeType == 1) {
            children.push(child);
        }
        child = child.nextSibling;
    }

    return children;
};

qq.getByClass = function (element, className) {
    if (element.querySelectorAll) {
        return element.querySelectorAll('.' + className);
    }

    var result = [];
    var candidates = element.getElementsByTagName("*");
    var len = candidates.length;

    for (var i = 0; i < len; i++) {
        if (qq.hasClass(candidates[i], className)) {
            result.push(candidates[i]);
        }
    }
    return result;
};
